I need help with the best method for exporting blackberry contacts to Gmail?

What's the best method for exporting contacts from blackberry into Gmail. If you are going to advise the use of csv files, please give simple instructions as my last attempt led to creation and exporting of a large file with no phone numbers. Secondly, do help with how to delete duplicate contacts in Gmail and outlook. The MERGE DUPLICATES in Gmail has not worked, with over 3000 duplicates